In general, in a power supply system, an emergency power source, such as a power generator, is separately provided in order to prepare for the case where a problem occurs in a normal power supply source. An emergency generator supplies alternative power in order to prevent an interruption to the supply of power when the supply of commercial power is shut off along with an uninterruptible power supply (UPS) for short-period compensation.
Such an emergency generator selectively connects power supply-requiring loads selected from among the loads of a system. This is intended to selectively connect loads in order to connect loads in accordance with preset specifications for the amount of generated power of the emergency generator when the emergency generator applies power in the case where an emergency, such as a power failure, occurs.
As described above, in the conventional technology, when the power of the emergency generator is applied, loads are connected in accordance with specifications and thus the supply of power to some loads is cut off, so that a problem arises in that a power failure situation occurs in the loads.
In particular, in order to prevent a power failure state in some loads, an emergency generator should be driven at the power generation capacity that satisfies all load demand within a system.
In this case, since the corresponding power generation capacity should be maintained regardless of a variation (reduction) in the load demand, problems arises in that the driving efficiency of the emergency generator is degraded and economic efficiency is lowered, and a negative influence is exerted upon the lifespan of the emergency generator.